Method for erecting a structure for an emergency power line, apparatus and kit of parts therefor

ABSTRACT

Method for erecting an emergency mast ( 1 ) for a power line comprising mast elements placed one on top of another, comprising the following steps: arranging a guide device ( 19 ) at the location where the emergency mast has to be placed; arranging a first mast element ( 5 ) adjacently of the guide device; raising the first mast element by means of the guide device to a height such that a following mast element can be placed under the first mast element; placing a following mast element under the first mast element and connecting the following mast element to the mast element situated thereabove; raising the thus obtained combination by means of the guide device to a height such that a following element can be placed under the combination; repeating the latter two steps until the mast has reached the required height; and removing the guide device.

BACKGROUND OF THE INVENTION

The present invention relates to a method for erecting an emergency mastfor a power line comprising mast elements placed one on top of another.

Emergency masts for power lines are used after one or more of theoriginal masts have been destroyed by for instance a natural disastersuch as an earthquake or tornado, another type of disaster or bysabotage. Emergency power masts can also be deployed to replace a faultyunderground cable connection or as temporary connection to replace acable or above-ground power line which is to be repositioned. There istherefore a need for a mast which can be erected quickly in suchemergency situations. This mast can be used per se when only a singlemast has been damaged by the disaster, or a series of masts can be usedwhen a significant part of such a power line has been destroyed. Knownfrom the prior art, for instance the KEMA brochure and ELECTRON“Emergency lines . . . , you may need them sooner than you think” is anemergency power pylon which is assembled lying on the ground andsubsequently erected by means of a crane, by means of a pivotinghoisting boom or using a helicopter. It is also known to assemble a mastin the erected situation by mounting each of the subsequent elements ontop of the already existing mast part using a boom suspended in cables.

All these known methods have drawbacks.

Assembly on the ground thus requires extensive lifting equipment whichis usually difficult to take to the intended location and which requiresmuch manpower. It is noted here that such emergency power pylons mustusually be erected at locations which are difficult to reach and whichare often not flat, so chat the available space is small and assemblyand erection in this manner involve difficulties.

It is of course simpler to construct the mast elements by stacking,although this is dangerous because operations take place increasinglyhigher in the mast, wherein the mast elements must moreover be hoistedupward. This also requires the necessary lifting equipment and inparticular the professional skill. In addition, the method istime-consuming because the guys must be constantly displaced.

GB-A 1 409 888 discloses a method for erecting a mast comprising mastelements placed one on top of another, comprising the following stepsof:

arranging a lifting device at the location where the emergency mast hasto be placed;

arranging a first mast element close by the lifting device;

raising the first mast element by means of the lifting device to aheight such that a following mast element can be placed under the firstmast element;

placing a following mast element under the first mast element andconnecting the following mast element to the mast element situatedthereabove;

raising the thus obtained combination by means of the lifting device toa height such that a following element can be placed under thecombination;

repeating the latter two steps until the mast has reached the requiredheight.

This known prior art relates to a temporary mast structure for a singleradio mast or single signal mast.

The use as a temporary mast in a power line necessitates the use ofseveral and sometimes large numbers of masts. The use of the prior artconstruction would imply the use of a separate lifting device for eachof the masts. This is undesirable for logistic reasons.

BRIEF SUMMARY OF THE INVENTION

The aim of the invention is to provide such a method and the mast whichresult in a mast fit for a power line.

This aim is reached in that

the lifting device is located next to the location where the mast is tobe erected;

the lifting device comprises at least one mast element from which atleast two lifting frames extend, and

after the mast has reached the required height, the lifting device isremoved.

These features result in the removability of the lifting device so thata single lifting device can be used for the erection of several mastsleading to important logistic savings.

According to a preferred embodiment, suspension means for thehigh-voltage cables are arranged on the elements for placing high in themast, while the relevant elements are situated at a low heightadjacently of the guide device, wherein a work platform is also present.

This measure prevents that such usually heavy insulators forming thesuspension means have to be handled by people at the top of the mast.This in any case involves dangers and requires much human effort.

According to another preferred embodiment, the mast elements are raisedby means of a manually driveable winch mounted on the guide element. Bychoosing a winch of small diameter and possibly a transmission, theforce necessary for pressing upward of the already partially mountedmast can be limited considerably. This has the advantage that this forcecan be exerted by manual effort so that no separate equipment isrequired for this purpose. This equipment is in any case not usuallyavailable in such emergency situations. It is also possible to make useof a light electric motor or a pneumatic or hydraulic drive.

It will be apparent that such an emergency mast will have to be guyed.It is noted here that the usual power pylons are not generally guyed;they take a wide form at their bottom. This is not possible withemergency power pylons; the components required for this purpose wouldbe much too large or far too many components would be needed, wherebyerection of such an emergency mast would take too long and require toomuch material. This is prevented by guying. Only after the mast hasreached the final height are the guys fastened to their ground anchorsand tensioned.

It is noted here that the guys are fixed to the mast elements by meansof junction boxes which are also suitable for fixing of the insulatingsuspension elements.

The invention moreover relates to an apparatus for erecting an emergencypower pylon formed from mast elements, comprising a frame for placing onthe ground, guide means mounted on the frame at a distance from theground at least corresponding with the height of the mast elements forguiding the mast elements of the power pylon for erection, and a winchmounted on the frame.

This apparatus is particularly suitable for performing a methodaccording to the present invention; mast elements are herein placed andconnected in each case to the mast element lying above, wherein the thusobtained assembly is pulled upward by means of the winch. Wound onto thewinch for this purpose is a cable which can be coupled to the lowestmast element to be moved upward.

According to a preferred embodiment, the guide means comprise at leasttwo guide sub-frames which are arranged at different heights on theframe and which are each adapted to enclose the mast elements. Anadequate guiding of the mast elements thus takes place, which isnecessary up to the stage at which guys are attached, since up untilthen the mast elements are only supported by the guide device.

According to another preferred embodiment, the frame is assembled fromat least two mast elements. It will be apparent that this measure limitsthe number and variety of the components.

The present invention therefore provides a kit of parts for assemblingat least one emergency power pylon, comprising at least mast elementsand suspension means, and a guide device is included in the kit ofparts.

In preference the kit of parts is placed in a closable containertogether with the mast components. The container can thus be takenquickly to the location where the emergency power pylon has to beerected. The container is provided for this purpose with all relevantparts. The container can be easily transported with usual transportingmeans, for instance a truck, train or ship.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will be elucidated hereinbelow with reference tothe annexed drawings, in which:

FIG. 1 shows a perspective view of a first embodiment of a power pylonerected with the method according to the present invention;

FIG. 2 shows a perspective view of a second embodiment of a power pylonerected with the method according to the present invention;

FIG. 3 is a perspective view of an apparatus for erecting a power pylonaccording to the invention; and

FIG. 4 is a perspective view of the top part of the power pylonaccording to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a power pylon designated as a whole with 1. Mast 1comprises a foot-plate 2 which is fixed in the ground by means of pins3. It will be possible to apply other fastenings for foot-plate 2depending on the ground type.

Constructed on the foot-plate 2 is the actual mast in the narrower sensewhich is formed by mast elements 5. Each of the mast elements 5 isformed by a lattice structure to keep the weight as low as possible witha sufficiently great strength.

Mast elements 5 are mutually connected by releasable connections, forinstance screw connections. The mast elements each have dimensions suchthat they can be easily handled by four people. This avoids thenecessity of lifting equipment for handling of the mast elements. Thelowest mast element is fixed to foot-plate 2 by means of apyramid-shaped element 6. This latter is fixed to foot-plate 2 by meansof a universal joint 7 in order to prevent stresses in the connection inquestion and to enable placing of the mast at all times in the correctvertical position.

To hold the mast upright use is made of guys 8. Guys 8 are fastened to ajunction box 9 which is mounted between mast elements 5. At their bottomend the guys 8 are secured to anchors 10. In the embodiment shown inFIG. 1 there are two series of guys 8 one above the other. One series isusually sufficient. It will be apparent that in order to achieve anadequately fixed situation, guys 8 are necessary in at least threedirections.

Suspension means are further arranged to bear the high-voltageconductors. In the present embodiment a suspension device 11 is hereinarranged for a single conductor. There may also be two per suspensionpoint. Each suspension device 11 comprises an insulator 12 which extendssubstantially horizontally and which is fixed on the mast side to ajunction box 9 and an obliquely extending insulator 13. The obliquelyextending insulator 13 is also fixed on the mast side to the mast bymeans of a similar junction box 9. The distal ends of both insulators12,13 are mutually connected and provided with supporting means forsupporting the high-voltage conductor(s) 14.

It is herein noted that the horizontal insulator 12 is only under strainof pressure. Conductor 14 is fixed to the connecting point of bothinsulators by means of a mounting element 15. This latter is adapted toallow the conductors to rotate when they are being tensioned, but islikewise adapted to fix the conductors to the mounting element once theconductors have been arranged. A total of six such devices are arrangedin the present embodiment, in this case two per stage. It will beapparent that other configurations are possible.

At the top of the mast is arranged a supporting device 16 for a neutralline 17 and a hoisting beam 28 for hoisting up insulators 12,13.

FIG. 2 shows a similar mast, which varies from the mast depicted in FIG.1 in the different configuration of the insulators. The mast shown inFIG. 2 is for instance suitable for placing in a corner point of a powerline where the resultant of the forces exerted by the conductors on themast substantially does not equal zero. Only a single insulator isherein used per conductor side. However, two insulators are used perconductor to transmit the forces of the conductor to each side.

The erection of such a mast will be shown with reference to FIGS. 3 and4 hereinbelow.

Ground plate 2 is initially placed on the ground 4 and fixed with pins3, whereafter the apparatus for erecting the mast is constructed on theground plate. This apparatus generally designated 35 is assembled fromat least two, and in the present embodiment three, mast elements 5 whichare mutually connected and subsequently erected using the winch. Theapparatus is then guyed using guys 18 so that a sturdy entity isobtained.

Guide frames 19 are then arranged, wherein the distance between bothguide frames 19 in vertical direction is smaller than the size of one ofthe mast elements and wherein the distance between the ground plate andthe lowest guide device 19 is greater than one of the two elements. Inthe embodiment shown here the guide frames 19 are placed between theelements. This implies that the element 5 enclosed between guide frames19 must be shorter than the normal mast elements 5 forming part of mast1 so as to allow the guide frames to guide the mast elements.

Guide frames 19 are each fixed between the relevant mast elements 5 bymeans of for instance a bolt connection or by means of collars. On theirinside the guide frames are provided with guide rollers 20 for upwardguiding of the mast elements 5 to be erected.

Two pairs of step-on plates 21 are further arranged which serve assupport during assembly.

The lifting device is then arranged. This is formed by a schematicallyshown winch 22, a first pulley 23 and a second pulley. Round the winch22 is laid a cable 25 which is also trained round all other pulleys. Thewinch is preferably driven by a pneumatically or hydraulically drivenmotor. It is also possible however to make use of manual effort.

Erection of mast 1 is then initiated. For this purpose a first mastelement 5 is arranged on the ground plate and erected. Use is madeherein of a pulley 27 mounted on one of the guide frames and a cabletrained thereover, one end of which is fastened to the element forerecting.

A hook fixed to the free end of cable 25 is here coupled to the bottomof the mast element and the relevant mast element 5 is hoisted upwardusing winch 22. A subsequent element 5 is then placed under the firstelement 5, whereafter the first element 5 is allowed to descend onto thelower element 5 using the winch, and both elements 5 are fixed to eachother with for instance a bolt connection.

The point of attachment of the lifting device is then displaced and thethus described, partly completed mast is hoisted upward.

The same procedure is then repeated, this being continued until the masthas reached the required height.

It is noted here that junction boxes 9 are arranged between the relevantmast elements 5 during assembly. The junction boxes serve not only forfixing of the guys to be arranged later but also for mounting of thesuspension devices 11 for the conductors. Junction boxes 9 are thusarranged at the lowest possible level, while they are moved upwardduring the further assembly of the mast.

Use is further made of a hoisting beam 28 which is fixed onto theuppermost element 5. This hoisting beam serves in the first instance forhoisting to assembly height of the insulators 12, 13 for fixing to thejunction boxes 9. After being arranged at the desired height they arefixed to junction boxes 9 with the mounting means suitable for thispurpose. They are also suitable for later lifting of guys or conductorswhen the actual mast 1 is completed. Finally, the hoisting beam 28 canserve as support for a neutral conductor.

It will be apparent that a simple and safe method is hereby provided forerecting such a mast, for which little equipment is necessary and whichcan be performed in its entirety with the equipment supplied therewith.Finally, it is pointed out that it is particularly attractive to combinein a container all the parts for assembling one, two or three masts.This container can then be transported using the usual transport meansto the location where the mast has to be erected, so that the teamentrusted with erection will find all parts inside the container.

Although the above invention relates in the first instance to theerecting of vertical masts, it can also be used to erect V-shaped masts,as per se known from the brochure referred to in the preamble.

What is claimed is:
 1. Method for erecting a mast comprising mastelements placed one on top of another, comprising the following steps:arranging a lifting device adjacent the location where an emergency mastis to be placed, said lifting device comprising at least one mastelement from which at least two guide frames extend; arranging a firstmast element close of the lifting device; raising the first mast elementby means of the lifting device to a height such that an additional mastelement can be placed under the first mast element; placing theadditional mast element under the first mast element and connecting saidadditional mast element to the first mast element situated thereabove;raising the thus obtained combination of mast elements by means of thelifting device to a height such that a further additional mast elementcan be placed under the combination of said first and additional mastelements; repeating the latter two steps until the mast has reached therequired height, and removing the lifting device from said locationadjacent the emergency mast.
 2. Method as claimed in claim 1,characterized in that suspension means for high-voltage cables are fixedto the mast elements which are to be positioned high in the mast and inwhich said mast elements prior to being raised are situated at a lowheight adjacent the lifting device.
 3. Method as claimed in claim 2,characterized in that prior to placing of the lifting device a platformis arranged at the location where the emergency mast is to be erected,and that the lifting device is placed on the platform.
 4. Method asclaimed in claim 2, characterized in that the suspension means are fixedto the mast elements while said elements can be reached by a personstanding on a work platform.
 5. Method as claimed in claim 4,characterized in that prior to placing of the lifting device a platformis arranged at the location where the emergency mast is to be erected,and that the lifting device is placed on the platform.
 6. Method asclaimed in claim 1, characterized in that prior to placing of thelifting device a platform is arranged at the location where theemergency mast is to be erected, and that the lifting device is placedon the platform.
 7. Method as claimed in claim 1, characterized in thatthe mast is guyed after erecting of the mast.
 8. Method as claimed inclaim 7, characterized in that a hoisting beam is arranged on a firstmast element and suspension means for power lines are carried to theheight at which they are fixed to the mast element by said hoistingbeam.
 9. Method as claimed in claim 8, characterized in that subsequentto the mast being fully erected the hoisting beam is used for raisingmaterials for fastening power lines to the suspension means.
 10. Methodas claimed in claim 1, characterized in that the mast elements areraised by means of a winch connected to the lifting device.
 11. Methodas claimed in claim 10, characterized in that a hoisting beam isarranged on the first mast element and suspension means for power linesare carried to the height at which they are fixed to the mast element bysaid hoisting beam.
 12. Method as claimed in claim 11, characterized inthat subsequent to the mast being fully erected the hoisting beam isused for raising fastening materials for fastening power lines to thesuspension means.
 13. Apparatus for erecting a mast formed from mastelements, comprising a lifting device for ground placement, guide framesmounted on said lifting device at a height from the ground at least asmuch as the height of a mast element for guiding the mast elements ofthe mast during erection, and a winch connected to the lifting device,characterized in that the lifting device comprises a temporary mast fromwhich the guide frames extend said guide frames being spacedhorizontally on said lift at a distance of at least the width of a mastelement and protruding from said lift a distance exceeding the width ofthe mast element.
 14. Apparatus as claimed in claim 13, characterized inthat the winch is connected to a hydraulically or pneumatically drivenmotor.
 15. Apparatus as claimed in claim 14, characterized in that thelifting means comprise at least two guide frame combinations which arearranged at different heights on the lift and which are each adapted toenclose the mast elements.
 16. Apparatus as claimed in claim 14,characterized in that the lift device comprises at least two mastelements.
 17. Apparatus as claimed in claim 13, characterized in thatthe lifting means comprise at least two guide frame combinations whichare arranged at different heights on a portion of the lifting device andwhich are each adapted to provide side support for the mast elements.18. Apparatus as claimed in claim 17, characterized in that the liftdevice comprises at least two mast elements.
 19. Apparatus as claimed inclaim 13, characterized in that the lifting device comprises at leasttwo mast elements.